Economic research on migration tends to focus on workers, labour markets, or communities in receiving countries. However, labour migration and earnings could have important impacts on migrants’ home countries. This column explores these effects by focusing on circular migration from Malawi to South Africa in the 1960s and 1970s. Malawian districts that had the greatest exposure to migration shocks have better educated workers, even three decades later. These findings point to potential ‘brain gain’ effects for sending communities.

We traditionally think of migrants draining their home country of knowledge and skills, and, instead, giving their all to their host country. Based on patent and inventor data, this column looks at knowledge diffusion conveyed by highly skilled migrants both within their host country as well as back to their homelands. China, South Korea and Russia seem to profit from their diaspora’s knowledge generation but the same can’t be said for India.

Is the brain drain reversing? This column argues that increasing numbers of foreign-educated and economic emigrants are returning home. Evidence suggests that the best of the bunch bring with them strong corporate governance practises and an appetite for internationalisation. Through this ‘brain gain’, the return of skilled professionals boosts emerging markets’ economies.

Brain drain can be a good thing for the source country; one benefit is that some skilled workers eventually return. Unfortunately, there is little evidence on the incidence and nature of such return migration. This column presents new data on the return-migration decisions of foreign faculty based in US chemistry departments.

Some argue that the global competition for talented workers leads to a “brain drain” robbing poor countries of their brightest sparks and stifling development. Others suggest that the local economy can benefit through trade, investment, and knowledge transfer. This column argues that for developing countries with the largest high-skilled migration, neither is spot on – by far the biggest impact is on the migrants themselves.

The economic effects of immigration are often controversial. This column introduces the preliminary findings from a new database on immigration in Latin America and the Caribbean. While immigrants do not seem to displace domestic workers, they are often working in sectors unsuitable for their skills. Better policy could help the destination countries as well as the immigrants themselves.

This column surveys evidence describing the brain drain from Europe to the US. Europeans living in the US are exceptional – they are more educated, earn higher wages, are more likely to be employed, and more entrepreneurial than their American or European counterparts. Europe's growth prospects may be dramatically reduced by its best and brightest living in the US.

This column introduces a two-part series on how differences between universities are inducing a massive academic migration from Israel to the United States. The magnitude of this scholarly brain drain is unparalleled in the western world.